At 11:02 AM ET on Sat October 26, 2019 the S3 server exhausted all of its physical RAM resulting in an outage. Before bringing the server back online we applied an additional 30GB of ram to the system bringing it up to a total of 120GB.
At 7:53 PM ET on Sat October 26, 2019 the S3 server once again experienced a brief outage.
We presently believe the issue to be with CloudLinux and it not properly applying RAM limits to all accounts.
A ticket has been opened with CloudLinux and we are watching the server closely.